The present invention relates to the making Masa flour and Masa dough from corn which has not undergone complete milling. More particularly, this invention is directed to the production of Masa flour and dough which is made by grinding non degermed corn and cooking the ground non degermed corn with indirect and direct heat.
Masa Flour and Dough
Masa flour (dry corn flour which has usually been nixtamalized) and Masa (corn dough which has usually been nixtamalized) are raw materials which may be used for the preparation of tortillas, corn chips, tortilla chips, taco shells, nachos, snack foods and similar products.
Nixtamalization is the cooking of cereal grain, such as whole corn kernels, in a medium which usually contains an alkaline agent, such as water containing lime (Ca(OH)2). Thereafter there is steeping (soaking) of the cereal grain for a period of time, for example, for about three to about fourteen hours, subsequent draining of any remaining cooking liquor, washing of the cereal grains, and grinding of the cereal grains to make with drying a cereal grain flour, which may be added with water to make a cereal grain dough from which tortillas and related products may be prepared.
The production of Masa dough with whole corn kernels produces large amount of waste water because of the large amounts of water needed to soften and hydrate whole kernels of corn. Further, subjecting whole kernels of corn to a complete milling process to produce corn germ, corn meal, and degermed corn endosperm requires expensive equipment and space for housing such equipment. This has been found unnecessary to produce Masa flour or dough used to make tortillas, tacos, tortilla chips, taco chips and other corn snack foods. Further, large consumers of Masa flour and dough would prefer their sources of flour nearby to avoid lengthy shipping, shipping delays and/or costs and would even consider milling corn themselves if they could avoid the cost of an entire milling operation as a precursor to making Masa dough and other corn food products from Masa flour. In view of the foregoing, it would be highly beneficial to reduce the waste water generally created in the batch processing of corn to make Masa flour and dough, but also to reduce the milling equipment generally required to mill corn for such Masa flour, reduce the space required to house such equipment and also increase the yield of Masa flour produced per unit of inputted corn used to make the Masa flour and dough from the corn.
An object of this invention is to provide a new high yield process for the production of Masa flour and dough.
Another object of this invention is to provide a continuous process for the production of Masa flour and dough which not only minimizes or completely eliminates the production of waste water, but also reduces the amount of equipment and space for milling whole corn used to make the Masa flour and dough.
These and other objects, advantages, features and characteristics of the present invention will become more apparent upon consideration of the following description and claims.
This invention is directed to the partial milling of whole corn, moisturizing the partially milled corn and then cooking the moisturized partially milled corn to partially gelatinize starch in the partially milled corn to provide a partially gelatinized Masa dough which then may be dried into a Masa flour. According to the invention, the corn is partially milled by separating portions of the hull or bran and tip cap of whole corn to provide a decorticated product which is primarily endosperm and germ. The decorticated corn then is ground to a flour having a particle size of at least about 40 U.S. mesh or larger mesh size (for a smaller particle size). Generally the endosperm/germ flour has from about 88 to about 92 endosperm and from about 8 to about 12 germ. The ground flour then is mixed with water to provide a moisturized flour having from at least about 25 weight percent moisture. The process of the invention conveniently eliminates a number of milling steps such as tempering of corn and multiple stages of grinding, and provides a high yield of Masa flour based upon the total amount of corn inputted into the process. This permits the use of less space for milling equipment that is generally required in the milling of corn. As a result, the invention permits the establishment of xe2x80x9cmini-millsxe2x80x9d which require only removal of the tip cap and the dehulling and debraning corn and subsequent grinding of the dehulledxe2x80x94debraned corn. After the moisturization of the ground dehulledxe2x80x94debraned corn to a level of at least about 25, and generally from about 27 to about 50, the moisturized ground corn is cooked with indirect and direct heat to cook and partially gelatinize the starch in the flour which consists essentially of endosperm and germ. In this partial gelatinization, from about 10 to about 50 weight percent of the starch in the endosperm/germ flour is gelatinized.
With the popularity of corn food products, such as Mexican foods including tacos, tortillas both hard and soft, and corn snack foods such as corn chips, large volumes of corn flour now are required by the manufacturing suppliers of such food products. Corn flour suppliers and milling operation can reduce their costs by moving closer to their customers, even locating adjacent to their customers which make, cook and deliver cooked food products to the customer. While theoretically possible, it is not practical or cost effective to build an entire cereal milling operation adjacent to a manufacturer of tortillas, tacos and/or corn chips. Such mills are not only large and expensive to build, but inventors have found complete cereal mills have milling operations which are superflubus to the production of most products which require corn flour and/or Masa dough. In view of the latter situation, the process of the invention permits an abbreviated milling of whole corn and the processing of the corn which has undergone only xe2x80x9cpartialxe2x80x9d milling to provide a Masa dough or flour which is effective for providing a variety of cooked corn food products.
The process of the invention couples the partial or abbreviated milling of whole corn with the efficient cooking and partial gelatinization of starch in a corn endosperm/germ flour. The process of the invention is effective for permitting the continuous manufacture of Masa dough and flour for tortillas, tacos and a variety of corn snack products such as corn chips. The xe2x80x9cpost millingxe2x80x9d portion of the process of the invention which includes the moisturization, cooking and partial gelatinization of the xe2x80x9cpartially milledxe2x80x9d corn flour of the invention not only is effective for providing a continuous process for making the Masa flour and dough of the invention, but also is effective for reducing waste water generally required to make Masa dough at commercial volumes. Hence, space and equipment required to make Masa flour is reduced by only dehulling, debraning and grinding corn, but space and waste water also is reduced in wetting and cooking the ground endosperm/germ flour to make Masa dough according to the invention.
In an one aspect, during hydration, the corn endosperm/germ flour is mixed with water having a temperature of at least about 10xc2x0 C., but not at a temperature that would substantially gelatinize the starch in the blend. Generally the temperature of the water/flour blend should not exceed about 60xc2x0 C. The mixing of the water/flour blend should be effective to substantially, uniformly distribute water throughout the flour to the moisture level of the at least about 20 weight percent in the flour. In another aspect, the hydrated corn endosperm/germ flour has a moisture content of from about 20 to about 50 weight percent water, based upon the weight of the flour and water blend.
After hydration, the hydrated endosperm/germ flour is tempered for a time to equally distribute moisture throughout the flour. Generally, tempering times range from about 10 seconds to about 15 minutes, depending upon the type and the particle size distribution of the hydrated flour.
After tempering, the tempered hydrated flour enters a cooker to cook it in a cooking process which utilizes direct and indirect heat. The indirect heat keeps the cooker and dough at an elevated temperature which is effective for keeping the cooker clean of partially cooked residual dough. The direct heat, such as from the injection of steam into the tempered endosperm/germ flour, cooks the dough in combination with the indirect heat. The combination of indirect and direct heat brings the temperature of the tempered flour to a temperature of at least about 180xc2x0 F. as it leaves the cooker and partially gelatinizes the starch in the endosperm/germ flour. After the partial gelatinization, not more than about 15 to about 50 weight percent of the starch in the endosperm/germ flour is gelatinized. The tempered endosperm/germ flour is directly exposed to steam for about 10 seconds to about 2 minutes, and preferably from about 15 to about 30 seconds, with the cooking temperature also potentially being affected by a subsequent drying step.
After cooking the partially gelatinized endosperm/germ flour may be dried to a moisture content of not more than about 15 weight percent, preferably to about 10 to about 13 weight percent, at a temperature which is effective for not heat damaging or burning the product. After drying the dried partially gelatinized product is sized, such as by milling and sifting to a particle size of from about 16 to about 100 mesh, depending upon what type of food product which will be made with the partially gelatinized endosperm/germ flour.